Blog

CJG Blog

Center for Jewish Genetics blog

Part 2 - What do BRCA genetic test results mean?

In part one of this
series, you learned about BRCA genes and why someone with
a family history of cancer, like myself, may or may not choose to get tested.
In the second part of this series, I explore possible results of a BRCA genetic
test.

Okay now, what do the
results even mean? Here’s the nitty-gritty:

If you got a negative
result, as a woman whose biological mother had ovarian cancer and a BRCA gene
mutation, it would mean:

The test did not find a known cancerous mutation
in the BRCA genes. If you get breast or ovarian cancer in the future then this
particular gene probably did not cause it. It also means that your biological
siblings are also less likely to have the mutation.

You have the same risk factor as the average
person (about 8%), even though your mother has the gene mutation. You cannot
pass on the mutation to your children, because you do not have it.

A negative result when no mutation has been identified in
your family does not answer many questions. It could be there are other genetic
factors that caused your family member’s cancer that were not included in the
genetic test, since cancer comes from many different things. Risk is always
increased if a cancer runs in your family. Lacking the specific genetic mutation just means that you do not have that
additional risk.

But, if you got a
positive result, it would mean:

The test showed that you have a BRCA1/2 mutation
that is known to cause hereditary breast and ovarian cancer.

Your family (including siblings and biological
children) would then also be at an increased risk for that genetic mutation. They
can also be tested to see if they have it, but that will be up to them and you,
if you decide to disclose your status.

Your “positive” status can help either guide
your treatment if you are diagnosed with breast or ovarian cancer in the future
or it can help create a screening plan that will make the development of cancer
less likely through early detection and preventative measures.

Though less common, you could receive an ambiguous result, which would
mean:

The test showed that you have a mutation, but it
has not been seen before or been associated with cancer. These mutations are
called “variants of uncertain significance” or VUS. With a VUS result, it is
unclear if the mutation can lead to cancer. Receiving a complicated result like
a VUS can sometimes be more difficult than receiving a positive result. A
genetic counselor can help you understand what we do know about the mutation so
far and what this means for you.

As researchers continue to study BRCA mutations
and as more people are tested, there will be more information about what it
means to have these mutations and how it affects your cancer risk. It helps to
keep in touch with a genetic counselor over time to see if the specific
mutation has been re-classified as cancer-causing or not harmful.

Should you have
genetic testing? The short answer is, it’s up to you. There is no right
answer. In Part 3 I will delve deeper into my reasoning for getting tested and
going through my results.

Anna Kheyfets is a
senior at the University of Chicago. She will be graduating March 2019 with a
degree in Anthropology and Biology. She is an avid reader, writer, New Yorker,
and proponent of women’s health and rights. She has been an intern at WomanLab
(www.womanlab.org) in the Lindau Lab at the University of Chicago since January 2018,
where she has contributed to blog content, analytics and the other research
efforts. What’s next? After graduation she will be continuing her research in
Women’s Health back in NYC during her gap year before she begins medical school
and is looking forward to some lengthy subway rides.

In 2018, the Sarnoff Center ran four webinars for clergy, entitled Everything You Need to Know About Jewish Genetics (But Are Afraid
to Ask). The webinar offers clergy tools to serve congregants as they navigate Jewish genetic health topics and is co-presented by genetic counselor Rebecca Wang, LCGC, and Rabbi Aaron Melman. Watch the video of the July 2018 webinar:

Have questions or want more information? Contact the Sarnoff Center at (312) 357-4718 or JewishGenetics@juf.org. Since the time of this recording, genetic counselor Melissa Ramos joined the Sarnoff Center team. You can reach her at MelissaRamos@juf.org.

If you or someone you know has breast or ovarian cancer, a conversation about genetic testing might come up. When I found out my mom had cancer, genetic testing, while not on top of mind, did indeed arise as we navigated her treatment. To read that blogpost on WomanLab, I would start
there. It gives you a little insight as to why I was even tested at 19 years old.

As I was deciding whether or not to be tested, I explored everything the internet had to offer on the resources about BRCA testing. Although I spent hours at a time Googling, I realized what I was looking for was not out there. All the resources I found were either too cold, scientific, and
removed, or too fluffy and highly opinionated. I wanted something that I could relate to, learn from, and maybe even help me make a decision. This is, in large part, why genetic counselors are such an asset. They bring you the most evidence-based information all through a warm, human touch. While I made my
decision without such a resource three years ago, I wanted to fill a gap to help others in making their decision about genetic testing.

Ok, but first let’s start with the basics: What are BRCA genes?

Genes are passed onto us by our biological parents and we pass them onto our kids, if we have them. However, genes are not stagnant—they change, mutate, and recombine to make each of us entirely unique. That is why your genetic code is different from your siblings’, even if you come from the same biological
parents. There are a few genes that are common to predispositions for diseases. One example is the BReast CAncer susceptibility (BRCA) genes for Hereditary Breast and Ovarian Cancer Syndrome (HBOC).

The unmutated versions of the
BRCA genes code for tumor suppressor proteins. That’s just a fancy way of saying that when all is operating like it should, these genes make sure your cells don’t grow when they shouldn’t. Rapidly dividing cells form tumors and can possibly result
in a cancerous tumor.

By 70 years old, women with the BRCA1 gene mutation have about a 55-65% chance of developing breast cancer and women with the BRCA2 gene mutation have about a 45% chance, while the general population has about an 8% chance. It is important to remember that many other factors like your
environment, behavior, diet and, yes, even other genes affect your chance of developing cancer. If you have these
gene mutations, it does not mean you will definitely develop cancer, but being
tested can allow some preventive measures to be taken.

So you might be wondering, why would a woman choose not to be tested for genes that might cause cancer? If your mom were diagnosed with cancer, wouldn’t you want to know? What’s the downside? It is often not that easy. If you read
my other blog on WomanLab.org, you know that while I was quick to be tested with the guidance of my physician, my sister has made the opposite choice. She has decided, at least for now, genetic testing is not for her. Speaking to her, I learned that she chose to forego testing until she was older to avoid
what could come with a possible positive result. If she was tested at 16 years old and learned she had the gene mutation, she could live in fear that she is more likely to get cancer and pass it onto her future children at an extremely young age. Instead, she is choosing to take the time she needs to decide if and when
genetic testing is right for her. At a young age one might not be ready to make such a call. In fact, genetics professionals generally agree that testing is most appropriate for individuals in their early- to mid-twenties and older, but of course every person and situation is unique. That’s why it is important to talk
to a physician or a genetic counselor before making any swift decisions.

Anna
Kheyfets is a senior at the
University of Chicago. She will be graduating March 2019 with a degree in
Anthropology and Biology. She is an avid reader, writer, New Yorker, and
proponent of women’s health and rights. She has been an intern at WomanLab (www.womanlab.org) in the Lindau Lab at the University of Chicago since January 2018,
where she has contributed to blog content, analytics and the other research
efforts. What’s next? After graduation she will be continuing her research in
Women’s Health back in NYC during her gap year before she begins medical school
and is looking forward to some lengthy subway rides.

Lynch syndrome (LS) is a
heritable disorder that causes an increased risk of colorectal and many other
types of cancers. People inherit Lynch syndrome in an autosomal dominant manner,
which means that if one parent carries a gene mutation for LS, there is a 50
percent chance LS will pass to each child. When they’re working as they should,
the genes associated with LS protect you from getting certain cancers by
repairing mistakes made in DNA, but mutations in these genes prevent them from
working properly, which can lead to uncontrolled cell growth.

One in 440
Americans are carriers for Lynch syndrome.1 Ashkenazi Jews have specific LS founder mutations and have
among the highest rates of colorectal cancer of any ethnic group.2,3 In honor of Colorectal Cancer Awareness Month and National Lynch
Syndrome Awareness Day, here are three facts you might not have known about
Lynch Syndrome:

Genes
associated with LS can increase risk of breast and ovarian cancer.4,5
In addition to a higher risk of colorectal cancers, women with specific
variants of LS are twice as likely to develop breast cancer than women without
Lynch syndrome (15%). Women can have up to a 24 percent increased risk of ovarian
cancer with specific variants of LS.

Lynch
syndrome is the leading cause of hereditary colorectal cancer (CRC).6,7According to the American Cancer Society (ACS), 5 percent of CRC cases are associated with inherited genetic
mutations. ACS estimates that there will be 145,000 new cases
of colorectal in 2019 and LS will account for approximately 2 – 4
percent of these cancer cases.

An accurate
family health history is the best identifier of Lynch syndrome.8 Only 1 percent of the estimated 800,000 Americans with LS know they have the disorder. Patients do not typically find out they have LS until after a colorectal cancer
diagnosis. Doctors do not recommend CRC patients get genetic screening for LS because
of the rarity of the syndrome. Accurate family health history records remain the
best strategy for identifying LS.

If you have Lynch Syndrome, talk to your doctor about how
you can reduce your chances of getting cancers in the future. Having Lynch syndrome increases your chances
of getting colorectal, stomach, pancreatic, urinary tract, pancreas, brain,
small bowel, endometrial, breast, ovarian and uterine cancers.

Learn more about
family health history and find tools and worksheets tohelp
you collect key information
on our family
health history page.If
you have questions about your genetic health, reach out to Sarnoff Center or
your doctor.

I am
honored to be joining the Norton & Elaine Sarnoff Center for Jewish
Genetics as the genetic counselor and coordinator for the carrier screening
program! I am originally from Canada and completed my bachelor’s degree in
Medical Science specializing in Physiology and Pharmacology at the University
of Western Ontario. After graduation, I moved to Detroit to be a medical
technologist at the Detroit Medical Center. While I loved working in the lab, I
missed being with patients! After researching as many healthcare professions as
possible, I discovered genetic counseling. I was fortunate to attend the
Northwestern University Graduate Program where I received my master’s degree in
Genetic Counseling. I had the opportunity to work as a prenatal genetic
counselor in the Maternal Fetal Medicine division at Loyola University Medical
Center for nearly five years prior to joining the team at the Sarnoff Center. I
love being able to help people understand their families' genetic risks and
educate them on cutting edge technologies. I am especially excited to
participate in the community-based work of the Sarnoff Center. In my free time,
I enjoy watching movies, spending time with friends and family, and exploring
the different restaurants and neighborhoods that Chicago has to offer.

What is the most valuable gift you can give to your family? The gift of good health! There are many health conditions that run in families. Knowing your family health history can alert you to the potential risk for a variety of
genetic disorders
. Talk to your relatives for warning signs and
assess your risk
for hereditary cancers.

Did you know: Ashkenazi Jews are 10 TIMES more likely to have BRCA mutations, which significantly increases lifetime risks for hereditary cancers, so what does this heightened risk mean for you?
Click here to learn more
.